Osgood-Schlatter disease is most commonly diagnosed in athletic kids at the age of 13-14. Its signs include swelling, pain nd tenderness of the bony prominence of the upper shinbone, pain in the knee that worsens with activity (running, jumping) and improves with rest, and tightness of the surrounding muscles. This disease may occur in just one knee, or both knees may be affected. Osgood-Schlatter can last from weeks to months. It can be diagnosed by a physical examination and x-rays. Osgood-Schlatter disease usually doesn't require formal treatment, but some steps can be taken to relieve the pain and inflammation such as use of pain relievers, cross-training, and limiting physical activities.